


Unknown Omega

by lickable_llama



Category: Iron Man (Movies), The Avengers (Marvel) - All Media Types
Genre: Alpha/Beta/Omega Dynamics, Belly Kink, Coercion, Dubious Consent, M/M, Omega Tony Stark, Spanking, Weight Gain
Language: English
Status: In-Progress
Published: 2018-06-15
Updated: 2018-11-02
Packaged: 2019-05-23 16:12:13
Rating: Not Rated
Warnings: Creator Chose Not To Use Archive Warnings
Chapters: 3
Words: 3,806
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/14937602
Author URL: https://archiveofourown.org/users/lickable_llama/pseuds/lickable_llama
Summary: Au where omegas are very over weight  and unhealthy if not. Such as having the wrong pheromones ones that upset others without them noticing, no heats and unpleasant attitudes. Tony though he was a beta, he was wrong.In other words the Avengers collectively fatten tony up





	1. The Test

**Author's Note:**

> If you don’t like weight gain don’t read.  
> This idea popped into my mind. I’m thinking about adding mpreg later, but not sure if people would want that. I might forget while writing and just not put it in. But anyway thoughts?

“You need to do the test Stark” Fury says looking down at Tony, bound to a hospital bed.

“Fuck you Fury, you god damn pirate, I’ve done the fucking test before and I’m a god damn beta, you prick. Now let me out of here now” Tony yells at Fury, struggling against his bonds.  
“No, you’re the only avenger without an official test having been done on them. We need to know for sure if you are beta or not. And if you won’t do the test then your off the team.” Tony stops struggling to stare at Fury.  
“But you can’t do that the others wouldn’t let you. You can’t, right?” Tony said starting to look doubtful.  
“Actually I’ve spoken to the other avengers and they agree. If you have been classified wrong, then you could be detrimental to the team.” Fury says heading towards the door. “I’ll give you some time to decide” he says before closing the door. The team who had been watching through the surveillance system turned to fury.  
“Don’t you think you were a bit harsh? He’s just upset because you locked him up” Bruce says softly, looking down at the floor.  
“We gave Tony the chance to come in and just do the test, but he refused. If I’m right and he’s an omega he needs help. You know how unhealthy it is for omega to be underweight.” Fury says.  
Steve puts a hand on Bruce’s shoulder “You know he’s right Bruce. This is for Tony.”

 

Eventually Tony agrees to take the test. “So, Fury what’s the results huh? I’m a beta aren’t I” Tony says smugly. “I’m going to go now” holding out his hand Fury stops Tony.  
“Actually Stark you’re wrong you’re an omega” he says handing Tony the test results.  
“Your wrong I’m a beta, I've always been a beta. Dad said I was a beta.” Tony says voice monotone.  
“Tony I know it’s hard but your omega and always have been. Did your dad ever show you your test?” Fury asked knowingly.  
“Well no, but he said” Tony says quietly.  
“ I know, it’s why I bought you in. Made you do the test, you show all the signs of an underweight omega. Your pheromones upset people even before you walk into a room and you have an unpleasant attitude and erratic emotions.” Fury says softly.  
“ but I’ve never had heats, if I was omega I would have had heats” Tony says looking up from the paper in his hand.  
“Sometimes an underweight omegas body will hold off on heat until they get up to a healthy weight” he says putting a hand on Tony’s shoulder. “I’ll have the doctors at shield give you a diet plan to help you gain weight in a way that’s safe. You can have Bruce look over it as well to tweak it to your tastes. I know this is shocking, but we have to start soon, so you can get better.”

 

“Okay Tony your new rules, one you have to stick to the diet plan. You can eat what’s not restricted as much as you want but you can’t eat less then it says you have to or something restricted. And you can’t eat less one day because you ate a lot the day before okay?” Steve says making sure Tony is paying attention.  
“Yeah yeah now that I’m omega I’ve got to be submissive. Let you fatten me up and boss me around got it.” Tony says heatedly, crossing his arms to cover himself.  
“Tony this is to help you, and you know it is. Please let us.” Steve sighs leading him over to the couch and setting him on his lap.  
“ I know but I’m just scared, I’m not sure what I’m supposed to be doing.” Tony says quietly wrapping his arms around Steve now instead of himself.  
“Don’t worry Tony that’s why me and the team are here. That’s why we have made these rules for you. So, you have some guidelines to help you adjust. There’s only 3 of them so far but we will add more if we feel like you need it. I’m going to continue telling you the rules okay hun?” Steve says softly.  
Tony nods into Steve’s shoulder. “Okay sweetheart so the second rule is that if you don’t feel you can finish your food by yourself then come to one of us and we will make you eat it. If you don’t eat it, we will know, and we will have to force you to okay?” Steve says running his hand through Tony’s hair.  
Again Tony nods still not speaking. “Good now the last one is that you're not allowed in your lab without supervision. And that’s one of us, not Jarvis.”  
At this Tony raises his head looking angry “You can’t do that. It's not fair and you can’t make me.” Tony argued trying to push Steve away.  
“Yes I can Tony. These rules aren’t permanent but for now you need them. Your erratic and it’s dangerous for you to be in the lab alone. And you have too much control over Jarvis for us to believe he can always stop you. We just want to keep you safe this is the only way we could think of.” Steve says holding tony against him, so he can’t run away. “Just let us help you” Steve says softly. And Tony stops struggling and leans against Steve once more.  
“Fine" Tony says quietly. Eventually Tony falls asleep on Steve. Looking down at Tony all he can think is that he can’t wait until he starts gaining weight. He’s going to look so cute.


	2. Chapter 2

**Summary for the Chapter:**

> Tony isn't gaining any weight and Steve wants to know why.

**Notes for the Chapter:**

> Warning this chapter contains food avoidance that could be potentially trigger someone. This fan fiction is in no way meant to encourage eating disorders.

Bruce and Tony’s doctors had finished making a meal plan that would help tony to gain weight. He had been on it for two weeks and Steve was starting to get suspicious.  
Tony had been very docile and quiet about eating so far. The team had been informed by the doctors that Tony would most likely resist the changes in his diet and that they would have to coerce Tony to eat the food.  
But his plate was cleared albeit incredibly slowly, and though Bruce said it made sense as Tony wasn’t used to the portion sizes, Steve was beginning to get suspicious. Because even though Tony was apparently following the diet plan he hadn’t gained any weight so far. Bruce had told Steve to wait because sometimes it takes awhile for the body to gain, Steve was getting the feeling something wasn't right.

 

“Jarvis can you please play the security footage of Tony eating for the past two weeks.” Steve asks, staring at his tablet.  
“Certainly Captain rogers.” As Steve watches the footage of the first few days on the diet, he notices that after awhile of watching Tony eat they stop paying close attention to what Tony's doing.  
Slowly over the course of the meal the amount Tony’s eating would slow and he’d start pushing the food around his plate to make it appear he’d eaten more, occasionally taking a bite when an avenger looked over to check on him.  
Eventually when they would get up to do other things and tony would move the food into his pocket, get up and proceed to the kitchen where the bin was kept and empty the food into the bin. Then he would go back to his plate and make a big deal of him eating the last few bites.

 

A few days into the diet, after the first weight in, Tony changed his method of hiding his food. Probably worrying that someone would notice what he was doing and notice he wasn’t eating as much as he should be and therefore not gaining any weight.  
Instead he started bringing a glass of “milk” to drink with his food. But Steve noticed that Tony didn’t fill his cup all the way he only put a little bit in, the avengers hadn’t noticed because the glass was opaque.  
Wondering what his plan was he asked Jarvis to zoom in on Tony’s cup while he took a “sip” of milk. He watched as Tony spat the mouthful discreetly into the cup. Getting up multiple times to refill his cup. Changing the drink so he would have a reason to wash out his glass in the sink.

 

After going over all the footage, Steve told Jarvis to compile the clips showing Tony disposing of his food before asking the team to meet on his floor. Once they had all come up Steve asks Jarvis to play the video.  
“So how should we go about punishing him? he’s been breaking the rules we set. He knows he is supposed to stick to his diet plan” Steve asks one the video finished.  
“I think you should have a conversation and explain to him that you know he’s not following the plan and that he will have to be punished. Together you can discuss possible punishments.” Natasha says calmly.  
“Why should Steve explain it to him he knows the rules, I think you should not let him in the workshop at all that will make him think twice about disobeying” Clint says shrugging.  
“Because it’s Tony he won’t take that well and he’ll just push back harder. He might get defensive if the entire team confronts him so I think Steve should go by himself, that way Tony doesn’t feel like he’s being ganged up on and just shut down.” Natasha explains looking at Bruce and Thor silently asking for their opinions on what they should do.  
“I agree with Natasha, currently Tony’s emotions are erratic and the calmer we keep him the better. ” Bruce says cleaning his glasses.  
“I also believe that the captain should speak to him, as he is closest to him.” Thor says loudly.  
“Okay I will speak to Tony about him breaking the rules. But what am I supposed to do? How do I bring it up without upsetting him?.” Steve asks.  
“Well you should try your hardest to approach the conversation calmly.  
The aim is to make your relationship better by addressing the lie and figuring out a punishment that doesn’t make him shut us out but still teaches him a lesson, rather than turning it into an argument and just getting you both mad and upset.  
He may try to turn your words against you so that it turns in his favor to get out of his punishment.  
Try to shut him down before he can, you bringing the facts to the table won’t stop him from trying.  
Most importantly you need to keep calm, cool, and collected, keep the tone conversational, one of the worst things that will happen is Tony getting defensive. He will fight tooth and nail if he feels attacked in anyway.  
Explain to him how not eating properly effects the team and your relationship with Tony. You need him to feel bad about lying to us that way he will at least accept the punishments we give him.  
And then even if he stops feeling bad about not listening to us, later on he will at least think about the punishment and if it’s worth it or not.”

 

“Hey Tony I know you haven’t been following your diet” Steve says as he walks into Tony’s private floor.  
“Yeah I have, you guys have been with me at all meal times.” Tony says not turning away from the TV.  
“No you haven’t Tony, I've gone through the security footage.” Steve says turning the TV off “We agreed that you would follow the rules. Since you have broken the first two rules me and the team decided that we should make up some punishments for you.” Steve says.  
“But it’s just so hard Steve i’m not used to it and I start getting a tummy ache.” Tony whined pouting at Steve from under his lashes.  
“I know baby but you have to be punished. It will help motivate you. You can suggest some as well but me and the team have come up with some that are non negotiable” Steve says, watching Tony’s pout turn into a frown  
“So what are you gonna do spank me?” Tony asks sarcastically while rolling his eyes.  
“ If that’s one you want to suggest I don’t mind it. But the first punishment is that we are going to restrict your lab time. I haven’t worked out how much but I’m thinking maybe we stay down there two hours each. Maybe more if we decide you’ve been good and one of us don’t mind staying down there.” Steve says, holding up his hand when Tony opens his mouth to voice his opinion. “The next punishment is no iron man suit.” Steve finishes making a gesture that Tony could speak now.  
“Fuck off Steve, I’m not giving up Iron man “ Tony spits face twisted in anger.  
“The team and I think it’s for the best. We don’t know how you’ll react in the field. You have no control over your emotions, getting angry for no apparent reason and you broke our trust by lying to us. We only want what’s best for you Tony, and we tried to be nice and let you do it on your own bit instead you tricked us, hiding your food in your hand or spitting it out. We were so happy that you were finally being healthy.” Steve says softly trying to make Tony feel bad about lying like Natasha had advised.  
“Fine” Tony agrees quietly, eyes staring at his fidgeting hands. All anger suddenly gone. “I’m sorry, I won’t lie again” Tony mumbles still not looking up.  
“That's okay baby, from now on we’ll help you eat even if you feel like you can’t eat anymore.” Steve says, smiling at Tony.

**Notes for the Chapter:**

> Hey! sorry for the long wait. I have just started going to a new university course and so I have been sorta busy adjusting to that. I will try to write the next chapter soon.


	3. Upping the game.

**Notes for the Chapter:**

> Sorry for the long wait. I have been really busy with exams and assignments for my course. Here it is a new chapter I am going to be honest and say it will probably be awhile until I can write another chapter but I will do my best.  
> As usual tell me if I have made any mistakes. Hope you enjoy :)

 

Tony had been sticking to Bruce’s meal plan for 2 weeks now, Steve and the team being thorough in checking to see if he had actually consumed the food, and his body had already started to change.

Not by much but there was a slight curve to his belly now where there used to be none. His face had also rounded out and his ass was filling his jeans a bit more than before.

Steve was loving it. Watching Tony eat used to be a rare treat but now he was having to actually consume food rather then pick at it then return to his lab or pretending to eat it. Knowing that the amount of food would increase as time went on. Stretching out Tony’s stomach so he could eat more.

It’s also designed to make Tony hungry more often excited Steve. He hasn’t changed yet but that would begin eventually. Soon his stomach would start rumbling for food and Tony would stuff himself till he was full.

And maybe beyond full if Steve can convince him to. Maybe get him to start enjoying the tight feeling of being stuffed. Steve had started hovering around Tony asking him if he’s hungry would he like some food and leaving snacks around his lab.

Hoping he would find them and eat them. So far Tony hasn’t really noticed their appearance, only picking at them once or twice .

So far Tony hadn’t refused to eat any food after being caught out but Steve had a feeling he would soon throw a tantrum. He had seen Tony looking himself up and down in the mirror.

Running hands over his new flesh with a frown. Bruce was also going to up the size of the meals by quite a bit to help stretch Tony’s stomach. So Tony will have to eat till he’s stuffed unlike with the current meals which are while larger than normal ones don’t put a huge amount of strain on Tony to eat.

His belly not even bloated after finishing them. 

  
The lab visits had a schedule now as a punishment for lying to them about his diet. Each of them going down twice a week for 2 hours. More if they felt Tony deserved to stay down there longer and they had free time. Natasha was the only one so far to go down for extra time. Feeling guilty she didn’t notice Tony was an omega and that he wasn’t following his diet.

At first Tony tried to get Jarvis to let him go down, but Steve had convinced Jarvis that this was for Tony’s health so Jarvis refused. At first Tony would get upset and try to get them to let him go down. But he stopped when they said they wouldn’t let him go at all if he kept complaining. Though Steve didn’t mind hanging out in Tony’s workshop, he just wanted Tony to behave.

Clint complained about being bored and Bruce always tried to Convince Tony to go to his lab instead. But Steve just sat there drawing Tony. Marking the small difference in his form. Planning on making a timeline of his weight gain.  
  
Steve knew the day Bruce made Tony’s meals bigger was going to be the day Tony had to be reminded of the rules. While Steve didn’t want to hurt Tony or make him upset he was also excited to discipline Tony.

“I can’t eat all this” Tony says staring down at his huge plate.

“Sweetheart I need you to try your best and whatever you can’t eat I’ll help you to eat” Steve says kindly .

Staring at Steve dubiously Tony starts to eat. After eating his usual meal size Tony stops. “I’m full” he says pushing the plate away. “Tony you have to eat all of it and you know it. And I know your not that full” Steve sighs  pushing the plate back in front of Tony.

“Steve no I’m full.” Tony whines.

“Eat it or I’ll make you” Steve says looking into Tony’s eyes. Huffing Tony picks up the plate. Steve smiles happily until Tony drops the plate onto the floor.

“Oops, sorry”. Tony says unrepentant. Steve looks at the plate, and the mess on the floor, grateful it was not broken and sighs. Tony smirking triumphantly says “I’m going to go to my lab” and starts getting up to leave.

“No your not, your going to eat what’s on your meal plan. Though since I don’t know exactly how much you ate your going to have to eat the entire plate. After I of course punish you for making a mess and not eating your food.” Steve says grinning before he grabs Tony and puts him over his lap.

“Steve what the fuck are you doing? Piss off.” Tony yells struggling to get free.

“No Tony you need to be punished. You made a mess and refused to eat what you were told to” Steve says bringing his hand down on Tony’s ass hard. Tony squirming on Steve’s lap.

Steve admiring the way his ass jiggled slightly with each slap. His soft tummy pressing against his lap Tony’s hardening length against his thigh and his soft moans  interrupted by smacks.

“Are you enjoying this baby? What a naughty boy this is supposed to be a punishment” Steve growls in Tony’s ear giving it a quick nip, hard enough to make Tony yelp before going back to the punishment.

After another 10 smacks Steve places Tony on his own chair. Tony immediately reaching for his erection only for Steve to slap his hand away.

“Ah ah ah no touching this is a punishment” Steve says getting up and getting more food from the fridge and placing it in front of Tony. “Eat.” Steve says watching Tony pick up a fork and start eating without protest. Shifting on his sore ass trying to get comfortable.

“Good boy.” Steve says giving Tony a pat on the head before walking behind Tony to start massaging his stomach. Slowly one hand makes its way down to his dick making Tony let out a soft hum.

“Keep eating baby” Steve whispers in Tony’s ear when he pauses to thrust into Steve's hand. By the time Tony had finished it all he was panting for breath, his belly swollen with enough food to start pushing onto on his lap. Steve couldn’t wait for it to do that when it was empty.

 

His dick was as hard and heavy as his belly. “Amazing Tony. You are such a good boy” Steve says moving in front of Tony and licking his way into Tony’s mouth. Eventually pulling back to kiss his way down lingering again, on the neck leaving a few bite marks before sinking to his knees between Tony’s open legs.

“Such a pretty omega” he says slowly unbuttoning Tony’s jeans then sitting back to watch Tony’s belly unzip his tight jeans by itself. Tony lets a load moan out when Steve Gropes Tony’s reddened ass when lifting him up to help pull his pants down his thighs. Mouthing at the marks left by Tony’s to small pants.

He pulls his penis out, sucks on the tip savoring the salty taste on his tongue before licking it up and down the shaft. Hearing Tony’s moans from above encouraging him he curls his fingers around the base of Tony's cock and sucks slowly pushing his head down further until he has swallowed the whole thing.

“Steve-“ Tony moans and Steve pulls off and gets up.

“This is a punishment Tony” he whispers in his ear before grabbing the empty plates and starting to leave.

“No wait please” Tony calls desperately. “I’ll eat however much you want whatever the meal plan says just keep going please” Steve smirks turning around and heading back to Tony.

“You promise?” He asks getting closer to Tony.

“Yes just please I need-”  

“Okay Baby, you think you can eat a little bit more maybe a dessert?” Steve asks Watching Tony nod his head frantically before going to the kitchen and getting Tony a huge slice of chocolate brownie. After giving him the plate he knelt back down.

“ Your gonna have to feed yourself, but if you finish it I will spend another two hours in the lab with you this week” Steve says running his lips over Tony’s thigh before taking Tony in again. Sucking at the sensitive head of his dick before going back to deep throating Tony dick.

It doesn’t take much for Tony to come with a loud moan before he slumps back against the chair.

For a while he just sits there there dozing off with Steve rubbing his full belly, eventually though Steve lifts Tony up before walking him over to the couch so Tony could sit more comfortably while Steve massaged his cute little tummy.

Eventually Tony fell asleep and after taking Tony’s bloated form in one more time he got up to start preparing Tony’s next meal.  


**Author's Note:**

> If there’s any mistakes please tell me.


End file.
